• Journal of Korean Dental Science
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• v.12 no.2
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• pp.48-57
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• 2019

Purpose: To investigate whether there are specific surgical or clinical conditions where the use of autogenous bone (AB) is superior to the use of bone substitutes (BSs) for maxillary sinus floor augmentation (MSFA). Materials and Methods: We retrospectively analyzed 386 implants after MSFA in 178 patients. The implants were divided into five groups according to the sinus graft material used. Risk factors for implant failure in MSFA, and correlation between residual bone height (RBH) and graft materials in terms of implant survival were investigated. To investigate risk factors for implant failure in MSFA, implant survival according to graft materials, patients' sex/age, surgical site, RBH, healing period prior to prosthetic loading, staged- or simultaneous implantation with MSFA, the crown-to-implant ratio, prosthetic type, implant diameter, and opposite dentition were evaluated. Result: The cumulative 2- and 5-year survival rates of implants placed in the grafted sinus (independent of the graft material used) were 98.7% and 97.3%, respectively. None of the investigated variables were identified as significant risk factors for implant failure. There was also no statistical significance in implant survival between graft materials. Conclusion: There were no specific surgical conditions in which AB was superior to BSs in terms of implant survival after MSFA.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.3
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• pp.107-113
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• 1990

A series of cubical triaxial tests with independent control of the three principal stresses were performed on a compressible sand. All specimens which were formed by depositing the fine sand loosely, were used. It was found that slope of the stress-strain curve increased with increased b value, and the major principal strain at failure first remains approximetely constant for b values smaller than about 0.3 for drained condition and 0.6 for undrained condition respectively, and thereafter decreases with increasing value of b. The test results showed that the direction of the strain increments at failure form acute angles with the failure surfaces for both the drained and undrained condition. The results are thus not in agreement with the normality criterion from classic plasticity theory. However, it was found that the projections of the plastic strain increment vectors on the octahedral plane are perpendicular to the faiure surface in that plane.

• Radiation Oncology Journal
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• v.35 no.1
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• pp.48-54
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• 2017

Purpose: This study aimed to assess the effects of body mass index (BMI) on survival in cervical cancer patients who had undergone surgery and radiotherapy (RT). Materials and Methods: We retrospectively reviewed the medical records of 70 cervical cancer patients who underwent surgery and RT from 2007 to 2012. Among them, 40 patients (57.1%) had pelvic lymph node metastases at the time of diagnosis. Sixty-seven patients (95.7%) had received chemotherapy. All patients had undergone surgery and postoperative RT. Median BMI of patients was $22.8kg/m^2$ (range, 17.7 to $35.9kg/m^2$). Results: The median duration of follow-up was 52.3 months (range, 16 to 107 months). Twenty-four patients (34.3%) showed recurrence. Local failure, regional lymph nodal failure, and distant failure occurred in 4 (5.7%), 6 (8.6%), and 17 (24.3%) patients, respectively. The 5-year actuarial pelvic control rate was 83.4%. The 5-year cancer-specific survival (CSS) and disease-free survival (DFS) rates were 85.1% and 65.0%, respectively. The presence of pelvic lymph node metastases (n = 30) and being overweight or obese (n = 34, $BMI{\geq}23kg/m^2$) were poor prognostic factors for CSS (p = 0.003 and p = 0.045, respectively). Of these, pelvic lymph node metastasis was an independent prognostic factor (p = 0.030) for CSS. Conclusion: Overweight or obese cervical cancer patients showed poorer survival outcomes than normal weight or underweight patients. Weight control seems to be important in cervical cancer patients to improve clinical outcomes.

• Health Policy and Management
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• v.26 no.4
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• pp.343-351
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• 2016

Background: This study aims to analyze the effects of insurance types on the medical service uses for heart failure inpatients using propensity score matching (PSM). Methods: 2014 National inpatient sample based on health insurance claims data was used in the analysis. PSM was applied to control factors influencing the service uses except insurance types. Negative binomial regression was used after PSM to analyze factors that had influences on the service uses among inpatients. Subjects were divided by health insurance type, national health insurance (NHI) and medical aid (MA). Total charges and length of stay were used to represent the medical service uses. Covariance variables in PSM consist of sociodemographic characteristics (gender, age, Elixhauser comorbidity index) and hospital characteristics (hospital types, number of beds, location, number of doctors per 50 beds). These variables were also used as independent variables in negative binomial regression. Results: After the PSM, length of stay showed statistically significant difference on medical uses between insurance types. Negative binomial regression provided that insurance types, Elixhauser comorbidity index, and number of doctors per 50 beds were significant on the length of stay. Conclusion: This study provided that the service uses, especially length of stay, were differed by insurance types. Health policy makers will be required to prepare interventions to narrow the gap of the service uses between NHI and MA.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.2
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• pp.93-102
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• 1995

A series of test was performed by measuring the failure strength and the failure mode of fiber reinforced composite laminates joint containing two holes in Series or Parallel. $[0^{\circ}/45^{\circ}/90^{\circ}/-45^{\circ}]_s$ laminate with W/d(Side distance ratio) 4.0 and E/d(Edge distance ratio) 3.0 has the full bearing strength and are preferable in case of the good efficiency in two series hole. Comparisons were made between testing results and predicting values of the FEM model. Good agreements were fecund between them except the case of $E/d=2{\sim}3$. In the case of $G_h{\geq}3.0d$ and $G_v{\geq}3.0d$ since the interaction coefficients between two parallel holes and between two series holes were small, holes can be treated as independent. The Acoustic Emission(AE) and SEM method were utilized to find out the initial defects, damage and the fracture mechanism.

• Journal of Korean Academy of Nursing
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• v.46 no.6
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• pp.881-893
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• 2016

Purpose: The purpose of this study was to develop a heart health diary to promote self-care ability among patients with heart failure (HF), and to identify the diary's effect on self-care adherence, self-efficacy, and physical activity. Methods: A randomized control-group pretest-posttest design was adopted using block randomization. A calender-typed health diary was developed and it included a self-care checklist and education information on HF management. The experimental group were given guided counseling and education for 8 weeks and wrote a daily health diary during that period. Data were collected from the outpatient department of a tertiary medical center from February to April 2016. To verify the hypotheses, data for the experimental group (n=28) and control group (n=33) were analysed using the independent t-test with SPSS/WIN 21.0. Results: At the end of 8 weeks the experimental group had significantly higher scores for self-care adherence (t=-2.48, p =.016) and exercise related self-efficacy (t=-3.44, p =.001) compared to the control group. Conclusion: The findings show that the application of a patient-directed heart health diary is an effective nursing intervention for improving HF patients' self-care adherence and exercise self-efficacy. Strategies to promote dietary self-efficacy are necessary along with further studies including repeated research with an increasing intervention period. Healthcare providers need to encourage the utilization of a health diary for HF patients as a tool for evaluation and for implementation that leads to self-care.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1049-1056
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• 2018

Purpose: Local recurrence is the most common cause of failure in retroperitoneal soft tissue sarcoma patients after surgical resection. Postoperative radiotherapy (PORT) is infrequently used due to its high complication risk. We investigated the efficacy of PORT using modern techniques in patients with retroperitoneal soft tissue sarcoma. Materials and Methods: Eighty patients, who underwent surgical resection for non-metastatic primary retroperitoneal soft tissue sarcoma at the Yonsei Cancer Center between 1994 and 2015, were retrospectively reviewed. Thirty-eight (47.5%) patients received PORT: three-dimensional conformal radiotherapy in 29 and intensity-modulated radiotherapy in nine patients. Local failure-free survival (LFFS), overall survival (OS), and RT-related toxicities were investigated. Results: Median follow-up was 37.1 months (range, 5.8-207.9). Treatment failure occurred in 47 (58.8%) patients including local recurrence in 33 (41.3%), distant metastasis in eight (10%), and both occurred in six (7.5%) patients. The 2-year and 5-year LFFS rates were 63.9% and 47.9%, respectively. The 2-year and 5-year OS rates were 87.5% and 71.1%. The 5-year LFFS rate was significantly higher in PORT group than in no-PORT group (74.2% vs. 24.3%, p<0.001). In multivariate analysis, PORT was the only independent prognostic factor for LFFS. However, there was no significant correlation between RT dose and LFFS. OS showed no significant difference between the two groups. Grade ${\leq}2$ acute toxicities were observed in 63% of patients, but no acute toxicity ${\geq}$ grade 3 was observed. Conclusion: PORT using modern technique markedly reduced local recurrence in retroperitoneal sarcoma patients, with low toxicity. The optimal RT technique, in terms of RT dose and target volume, should be further investigated.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.35-48
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• 2022

This study was conducted to analyze the effect on entrepreneurial intention and empirically analyze which factors have the greatest influence. To this end, self-achievement motivation, indirect experience, role model, awareness of entrepreneurs, and fear of business failure were set as independent variables as factors influencing entrepreneurial intention. In order to empirically analyze this, 399 valid samples for the general public were analyzed. SPSS 25.0 was used for statistical analysis. As a result of the empirical analysis of this study, self-achievement motivation, indirect experience, role model, awareness of entrepreneurs, and fear of business failure all had a positive and significant effect on entrepreneurial intention. The results of this study confirmed that self-achievement motivation had the greatest influence among the factors affecting entrepreneurial intention. It is significant in that indirect experiences and role models such as theoretical entrepreneurship lectures, special entrepreneurship lectures, and parents or acquaintances influence entrepreneurial intention.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.322-331
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• 2017

District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.686-692
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• 2001

Background : Outbreaks of multidrug-resistant tuberculosis(MDR-TB) are caused by the low rate of treatment response due to limitation in number of available drugs and high rates of adverse drug side-effects. This study analysed the risk factors for MDR-TB patients, who did not respond to treatment, with an aim to improve the rate of treatment response. Methods : Retrospective study of 111 MDR-TB patients at National Mokpo Tuberculosis Hospital from Jan. 1996 to Dec. 1998 was made. The patients were separated into two groups ; group I comprised of patients who were treated successfully and group II comprised of those were not treated successfully. In order to analyze the risk factors for treatment failure, differences between the two groups were compared and the confidence limit regarding the results were tested using an independent t-test. chi-square test and a Fisher's exact test. Results : The treatment failure rate of MDR-TB patients was 32% (36 patients), and treatment success rate 68%(75 patients). This study found no significant difference between two groups in terms of age, sex, family history, extent of the disease on the chest X-ray, the number of sensitive drugs in the treatment regimen, and the number of sensitive bactericidal drugs in the treatment regimen (p>0.05). However, a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used showed a significant difference(p<0.05). Conclusion : The rate of treatment failure in MDR-TB was increased by a past history of pulmonary tuberculosis, cavitary lesions on the chest X-ray, the number of treatments, the number of resistant drugs and the number of drugs used. For improving the treatment response of MDR-TB, every effort should be made to reduce the drug resistance caused by failure of the first treatment.